The invention relates to a thin filter cigarette with a diameter of roughly 6 mm and a length of 90 to 100 mm and a smoke yield of at most 1 mg condensate.
Thin cigarettes of these mentioned dimensions have already been known for many years, albeit not as xe2x80x9clightxe2x80x9d or as xe2x80x9cultra-lightxe2x80x9d cigarettes but with packing densities and drawing resistances and also paper porosities which in no way achieve the values of a present-day ultra-light cigarette with 0.1 mg nicotine/1 mg condensate. Specialists have hitherto believed that an ultra-light cigarette could not even be made with smaller diameters than 8 or 7 mm.
The object of the invention is to create a thin filter cigarette with a diameter of roughly 6 mm which is to be unequivocally classified as an ultra-light cigarette on the basis of its nicotine/condensate values of 0.1/1 and which achieves a customary drawing coefficient during smoking.
The invention is explained in more detail below with the help of examples:
While a tobacco strand of 5-7 mm in diameter and a packing density within a range of 100-200 mg/cm3 may be provided, a tobacco strand with a diameter of 6.1 mm was manufactured, its packing density being 184 mg/cm3. The length of the tobacco strand was 70 mm. The tobacco strand was packed such that a drawing resistance of 100 daPa (deca pascal) resulted, a suitable range being 80 to 120 daPa. A cigarette paper with a porosity of 24 CORESTA units (CU) was chosen as casing for the tobacco strand. A suitable range would be 8 to 60 CORESTA units. The expanded tobacco content of the tobacco, as measured by the so-called INCOM method, was 55%. In other versions, the expanded tobacco content can lie between 40 and 100%. xe2x80x9cExpandedxe2x80x9d tobacco refers to a tobacco which is produced by the expansion method in accordance with DE-PS 29 03 300, 31 19 330 or 34 14 625. These methods are also called xe2x80x9cINCOM methodsxe2x80x9d. The above parameters may, however, be varied. For example, the tobacco strand may have a length between 65 and 75 mm.
The tobacco strand has a drawing resistance of 0.7 to 1.7 daPa/cm.
A double filter without cavity was attached to the thus-manufactured tobacco strand, the strand-side filter section consisting of paper, containing up to 100% spun cellulose fibers, and the mouth-side filter section of cellulose acetate. The overall length of the double filter was 27 mm, the length of the strand-side paper filter being 12 mm and the length of the mouth-side cellulose acetate filter 15 mm. Two rows of laser perforations, via which ventilation air can be introduced into the filter, ran through the casing at a distance of 12 and 13 mm from the mouth-side end of the cellulose acetate filter and thus at a distance of 2 and 3 mm respectively from the paper filter section. Since the perforation lines are situated in the area of the cellulose acetate filter section, the ventilation air flows only through this section and thus does not influence the flow through the paper section. The result of this is that the flow of the mainstream smoke through the paper filter section is relatively laminar, and a good nicotine and condensate reduction can take place. In the adjoining cellulose acetate filter section, on the other hand, the mainstream smoke is whirled by the ventilation air, which contributes to a clear improvement in taste.
A further result of the combination of a paper filter with a cellulose acetate filter is that the smoked-out cigarettes are much better biologically degradable, since more than half of the cigarette butt requiring disposal consists of biologically degradable material.
It will be appreciated that, while Table 1 gives a preferred relative retention of 92% and 8% for the tobacco-side filter element and mouth-side filter element, respectively, the relative retention of the tobacco-side filter and the mouth-side filter may be greater than 90% and less than 10%. Also, the nicotine/condensate xe2x88x9210 strand depletion ratio may be equal to or greater than 1.0, the exemplary ratio of 7.6 being given in Table 1. Further, while Table 1 gives an exemplary length of the filter as 27 mm and the mouth-side filter as 15 mm, the filter length may lie in a range of 25 mm-30 mm in length and the length of the mouth-side filter may lie in a range of 13-18 mm. The degree of ventilation may also lie in a range of 70-95%. Further, the tobacco-side filter element and the mouth-side filter element may have a drawing resistance of at most 60 daPa/cm and 30 daPa/cm, respectively. The mouth-side filter may have an individual denier value of at least 5-8 and a filament cross-section in the shape of a Y. The mouth-side filter may have an overall denier value of at least 15,000 to 20,000. Also, a preferred cigarette paper has an area weight of 20 to 50 g/m2 (See the examples in Table 3).
The individual parameters of the embodiments are reproduced at the end of the description in the form of Tables 1 to 4.
Cigarette smoking is increasingly criticized, since non-smokers in particular feel disturbed by the smoke and its smell. The cigarette according to the invention from Example 1 already shows clear advantages here compared with most cigarettes customary in the trade, as they give rise to ca. 40% less sidestream smoke because of their low smoked tobacco weight alone, and thus lead to correspondingly less smoky premises, a lesser impression of smell in the area, both fresh and stale, and a reduced smell on clothes, hair and items of furniture such as curtains, carpets etc. (see Table 4) .
Sidestream smoke refers to the smoke which rises from the zone in front of the glowing tip as the cigarette burns. Distributed in the ambient air, it is customary to also call this smoke xe2x80x9cenvironmental tobacco smokexe2x80x9d (ETS) or xe2x80x9csecond-hand smokexe2x80x9d. In order to compare the amount of smoke which is given off into the ambient air by tobacco products during smoking, it is customary to smoke a defined number of specimens of the study sample in question in an area with defined volume and suitable devices for taking samples for the measurement. The amount of smoke can e.g. be determined by precipitation of the smoke particles on a piezobalance from a defined sample volume. The particle masses measured by this method are in each case given in Table 4 as the average of three measurements, in order to carry out a comparison of the amounts of smoke produced by the embodiments of the cigarettes according to the invention with comparison cigarettes customary in the trade.
Following on from the sampling, the area was assessed for appearance and smell by subjects of a trained panel (i.e. a group) comprising smokers and non-smokers. The subjects rated their impression with the help of the optical test criterion xe2x80x9cdegree of smokinessxe2x80x9d and the smell-related test criterion xe2x80x9csmells of cigarette smokexe2x80x9d on a scale from 0 to 100. The numerical results of this sensory test were statistically evaluated, compressed into groups and assigned to the following definition scaling of the test criteria xe2x80x9csmokinessxe2x80x9d and xe2x80x9csmells of cigarette smokexe2x80x9d: none . . . , a little . . . , not much . . . , pronounced . . . , very pronounced. The results are listed in columns 4 and 5 of Table 4. The embodiment displays a lesser smoke impression than cigarettes customary in the trade, both quantitatively (xe2x88x9243%) and qualitatively.